<template>
  <div id="home">
    <nav-bar class="home-nav"><div slot="center">V-MALL</div></nav-bar>
    <tab-control :titles="['流行', '新款', '精选']" @tabClick="tabClick" ref="tabControl1"
                  class="tab-control"
                  v-show="isTabFixed"/>
    <scroll class="content" 
            ref="scroll" 
            :probe-type="3" 
            @scroll="contentScroll"
            :pull-up-load="true"
            @pullingUp="loadMore">
      <home-swiper :banners="banners" @swiperImageLoad="swiperImageLoad"/>
      <recommend-view :recommends="recommends"/>
      <feature-view/>
      <tab-control :titles="['流行', '新款', '精选']" @tabClick="tabClick" ref="tabControl2"/>
      <goods-list :goods="showGoods"/>
    </scroll>

    <back-top @click.native="backClick" v-show="isShowBackTop"/>
    
  </div>
</template>

<script>  
  import HomeSwiper from './childComps/HomeSwiper'
  import RecommendView from './childComps/RecommendView'
  import FeatureView from './childComps/FeatureView'

  import NavBar from 'components/common/navbar/NavBar';
  import TabControl from 'components/content/tabControl/TabControl';
  import GoodsList from 'components/content/goods/GoodsList';
  import Scroll from 'components/common/scroll/Scroll';
  import BackTop from 'components/content/backtop/BackTop'

  import {getHomeMultidata, getHomeGoods} from "network/home";
  // import {debounce} from "common/utils"
  

  export default {
    name: "Home",
    components: {
      NavBar,
      HomeSwiper,
      RecommendView,
      FeatureView,
      TabControl,
      GoodsList,
      Scroll,
      BackTop
    },
    data() {
      return {
        banners: [],
        recommends: [],
        goods: {
          'pop': {page: 0,list: []},
          'new': {page: 0,list: []},
          'sell': {page: 0,list: []},
        },
        currentType: 'pop',
        isShowBackTop: true,
        tabOffsetTop: 0,
        isTabFixed: false,
        saveY: 0
      }
    },
    computed: {
      showGoods() {
        return this.goods[this.currentType].list
      }
    },
    created() {
      // 请求多个数据
      this.getHomeMultidata()

      // 请求商品数据
      this.getHomeGoods('pop')
      this.getHomeGoods('new')
      this.getHomeGoods('sell')
    },
    mounted() {
      // 监听item中图片加载
      // const refresh = debounce(this.$refs.scroll.refresh, 50)
      // this.$bus.$on('itemImageLoad', () => {
      //   refresh()
      // })
    },
    activated() {
      this.$refs.scroll.scrollTo(0, this.saveY, 0)
      this.$refs.scroll.refresh()
    },
    deactivated() {
      this.saveY = this.$refs.scroll.scroll.y
    },
    methods: {
      // 事件监听
      tabClick (index) {
        switch (index) {
          case 0:
            this.currentType = 'pop'
            break
          case 1:
            this.currentType = 'new'
            break
          case 2:
            this.currentType = 'sell'
            break
        }
        this.$refs.tabControl1.currentIndex = index
        this.$refs.tabControl2.currentIndex = index
      },
      backClick () {
        this.$refs.scroll.scroll.scrollTo(0, 0, 500)
      },
      contentScroll (position) {
        // 判断Backtop是否显示
        this.isShowBackTop = (-position.y) > 1000

        // 决定tabControl是否吸顶
        this.isTabFixed = (-position.y) > this.tabOffsetTop
      },
      loadMore () {
        this.getHomeGoods(this.currentType)
      },
      swiperImageLoad () {
        // 获取tabControl到offsetTop
        this.tabOffsetTop = this.$refs.tabControl2.$el.offsetTop
      },
      // 网络请求
      getHomeMultidata () {
        getHomeMultidata().then(res => {
          this.banners = res.data.banner.list
          this.recommends = res.data.recommend.list
        })
      },
      getHomeGoods (type) {
        const page = this.goods[type].page + 1
        getHomeGoods(type, page).then(res => {
          // console.log(res)
          this.goods[type].list.push(...res.data.list)
          this.goods[type].page ++

          this.$refs.scroll.finishPullUp()
        })
      }
    },
  }
</script>

<style scoped>
  #home {
    /* padding-top: 44px; */
    height: 100vh;
    position: relative;
  }

  .home-nav {
    background: var(--color-tint);
    color: white;
    /* position: fixed;
    left: 0;
    right: 0;
    top: 0;
    z-index: 3; */
  }

  .tab-control {
    position: relative;
    z-index: 9;
  }

  .content {
    /* height: 300px; */
    overflow: hidden;
    position: absolute;
    top: 44px;
    bottom: 49px;
    left: 0;
    right: 0;
  }

  
</style>
